Abstract:

A drum pad capable of providing an excellent percussion feeling and
securely adhering a base portion to a body portion made of rubber. The
drum pad has a rear-side clothlike material which is provided on a rear
surface of the body portion and into which the rubber of the body portion
is impregnated. The base portion is fixed to a rear surface of the
rear-side clothlike material via a fixing layer made of pressure
sensitive adhesive or adhesive and provided on the rear surface of the
rear-side clothlike material.

Claims:

1. A drum pad, comprising:a body portion made of rubber and having a rear
surface thereof on a side opposite from a side where the drum pad is
struck;a rear-side clothlike material provided on the rear surface of
said body portion; anda fixing layer made of adhesive and provided on a
rear surface of said rear-side clothlike material,wherein said body
portion is joined to a front surface of said rear-side clothlike material
by impregnating said rear-side clothlike material with the rubber of the
body portion.

2. The drum pad according to claim 1, wherein the rear-side clothlike
material is one of a knitted material and unwoven cloth.

3. The drum pad according to claim 1, further comprising:a base portion
fixed to the rear surface of said rear-side clothlike material via said
fixing layer.

4. The drum pad according to claim 1, further comprising:a front-side
clothlike material having a rear surface thereof to which said body
portion is joined and a front surface thereof opposite from the rear
surface of said front-side clothlike material,wherein said front-side
clothlike material comprisesa first layer portion on a side of the front
surface of said front-side clothlike material, the first layer portion
formed by intruding a stretchable resin material into said front-side
clothlike material, anda second layer portion between the first layer
portion and said body portion, the second layer portion being impregnated
with the rubber of the body portion.

5. The drum pad according to claim 4, wherein the front-side clothlike
material is one of a knitted material and unwoven cloth.

7. The drum pad according to claim 1, wherein the rubber comprises
silicone rubber having a siloxane bond.

8. A drum pad comprising:a pad portion having a surface thereof adapted to
be struck; anda base portion disposed on a rear side of said pad
portion,wherein said base portion comprises first and second metal plates
and a resin layer interposed between the first and second metal plates.

9. The drum pad according to claim 8, further comprising:a percussion
sensor configured to detect a vibration of said base portion to thereby
detect striking of the surface of said pad portion.

10. The drum pad according to claim 9, wherein the first and second metal
plates each have a thickness in a range of 0.3 mm to 2.3 mm, and the
resin layer has a thickness equal to or larger than 0.1 mm.

11. The drum pad according to claim 9, wherein the resin layer is thinner
than the first metal plate or the second metal plate, whichever is
thinner.

12. The drum pad according to claim 9, wherein the first and second metal
plates have a same construction.

13. A drum pad comprising:a body portion made of rubber and having a rear
surface thereof on a side opposite from a side where the drum pad is
struck;a rear-side clothlike material provided on the rear surface of
said body portion; anda base portion having at least a member formed with
holes extending therethrough in a front-rear direction, said base portion
being fixed at a side of the member to a rear surface of said rear-side
clothlike material via a fixing layer made of adhesive,wherein said body
portion is joined to a front surface of said rear-side clothlike material
by impregnating said rear-side clothlike material with the rubber of the
body portion.

14. The drum pad according to claim 13, wherein the rear-side clothlike
material is one of a knitted material and unwoven cloth.

15. The drum pad according to claim 13, wherein the holes are distributed
in a higher density in a region further away from an outer periphery of
said base portion.

16. The drum pad according to claim 13, further comprising:a front-side
clothlike material having a rear surface thereof to which said body
portion is joined and a front surface thereof opposite from the rear
surface of said front-side clothlike material,wherein said front-side
clothlike material comprisesa first layer portion on a side of the front
surface of said front-side clothlike material, the first layer portion
formed by intruding a stretchable resin into said front-side clothlike
material, anda second layer portion between the first layer portion and
said body portion, the second layer portion being impregnated with the
rubber of the body portion.

17. The drum pad according to claim 16, wherein the front-side clothlike
material is one of a knitted material and unwoven cloth.

19. The drum pad according to claim 13, wherein the rubber comprises
silicone rubber having a siloxane bond.

20. A manufacturing method of a drum pad comprising a body portion having
a rear surface thereof on a side opposite from a side where the drum pad
is struck, and a rear-side clothlike material provided on the rear
surface of the body portion, the method comprising:a disposing step of
disposing the rear-side clothlike material in the mold, a rear surface of
the rear-side clothlike material provided with a fixed layer made of
adhesive anda molding step of casting liquid resin material or
thermally-softened non-vulcanized rubber into a mold, to thereby form the
body portion made of rubber and join the body portion to the front
surface of the rear-side clothlike material by impregnating the rear-side
clothlike material with the liquid resin material or thermally-softened
non-vulcanized rubber.

21. The manufacturing method according to claim 20, wherein the rear-side
clothlike material is one of a knitted material and unwoven cloth.

23. The manufacturing method according to claim 20, wherein the rubber
comprises silicone rubber having a siloxane bond.

24. A manufacturing method of a drum pad comprising a front-side clothlike
material that has a front surface thereof on a side where the drum pad is
struck and a rear surface thereof opposite from the front surface, a body
portion having a front surface thereof affixed to the rear surface of the
front-side clothlike material and a rear surface thereof opposite from
the front surface thereof, and a rear-side clothlike material provided on
the rear surface of the body portion, the method comprising:a thermal
adhesion step of forming a first layer portion in the front-side
clothlike material on a side of the front surface thereof by intruding
the front surface of the front-side clothlike material with a molten
stretchable resin material which is solidified integrally with the
front-side clothlike material;a disposing step of disposing the
front-side clothlike material with the first layer portion in a mold;a
disposing step of disposing the rear-side clothlike material in the mold,
a front surface of the rear-side clothlike material opposite to the rear
surface of the front-side clothlike material, a rear surface of the
rear-side clothlike material provided with a fixing layer of adhesive;
anda molding step of casting liquid resin material or thermally-softened
non-vulcanized rubber into a mold from between the rear surface of the
front-side clothlike material and a front surface of the rear-side
clothlike material to thereby form the body portion made of
rubber,wherein a second layer portion in the front-side clothlike
material is formed by impregnating the front-side clothlike material with
the liquid resin material or thermally-softened non-vulcanized rubber
between the first layer portion of the front-side clothlike material and
the body portion, thereby joining the body portion to the rear surface of
the front-side clothlike material, andwherein the rear-side clothlike
material is impregnated with the liquid resin material or
thermally-softened non-vulcanized rubber, thereby joining the body
portion to the front surface of the rear-side clothlike material.

25. The manufacturing method according to claim 24, wherein the rear-side
clothlike material is one of a knitted material and unwoven cloth.

26. The manufacturing method according to claim 24, wherein the front-side
clothlike material is one of a knitted material and unwoven cloth.

28. The manufacturing method according to claim 24, wherein the rubber
comprises silicone rubber having a siloxane bond.

29. A manufacturing method of a drum pad comprising a body portion having
a rear surface thereof on a side opposite from a side where the drum pad
is struck, and a rear-side clothlike material provided on the rear
surface of the body portion, the method comprising:a disposing step of
disposing in a mold a rear-side clothlike material with a rear surface
affixed to a base portion via a fixing layer made of adhesive, the base
portion comprising at least a member formed with holes extending
therethrough in a front-rear direction; anda molding step of casting
liquid resin material or thermally-softened non-vulcanized rubber into a
mold from the side close to the front surface of the rear-side clothlike
material, to thereby form the body portion made of rubber and join the
body portion to the front surface of the rear-side clothlike material by
impregnating the rear-side clothlike material with the liquid resin
material or thermally-softened non-vulcanized rubber.

30. The manufacturing method according to claim 29, wherein the rear-side
clothlike material is one of a knitted material and unwoven cloth.

32. The manufacturing method according to claim 29, wherein the rubber
comprises silicone rubber having a siloxane bond.

33. A manufacturing method of a drum pad comprising a front-side clothlike
material that has a front surface thereof on a side where the drum pad is
struck and a rear surface thereof opposite from the front surface, a body
portion having a front surface thereof affixed to the rear surface of the
front-side clothlike material and a rear surface thereof opposite from
the front surface thereof, and a rear-side clothlike material provided on
the rear surface of the body portion, the method comprising:a thermal
adhesion step of forming a first layer portion in the front-side
clothlike material on a side of the front surface thereof by intruding
the front surface of the front-side clothlike material with a molten
stretchable resin material which is solidified integrally with the
front-side clothlike material;a disposing step of disposing the
front-side clothlike material with the first layer portion in a mold;a
disposing step of disposing in a mold the rear-side clothlike material in
a mold, a front surface of the rear-side clothlike material opposite to
the rear surface of the front-side clothlike material, the rear-side
cloth material with a rear surface affixed to a base portion via a fixing
layer made of adhesive, the base portion comprising at least a member
formed with holes extending therethrough in a front-rear direction; anda
molding step of casting liquid resin material or thermally-softened
non-vulcanized rubber into a mold from between the rear surface of the
front-side clothlike material and a front surface of the rear-side
clothlike material, to thereby form the body portion made of
rubber,wherein a second layer portion in the front-side clothlike
material is formed by impregnating the front-side clothlike material with
the liquid resin material or thermally-softened non-vulcanized rubber
between the first layer portion of the front-side clothlike material and
the body portion, thereby joining the body portion to the rear surface of
the front-side clothlike material, andwherein the rear-side clothlike
material is impregnated with the liquid resin material or
thermally-softened non-vulcanized rubber, thereby joining the body
portion to the front surface of the rear-side clothlike material.

34. The manufacturing method according to claim 33, wherein the rear-side
clothlike material is one of a knitted material and unwoven cloth.

35. The manufacturing method according to claim 33, wherein the front-side
clothlike material is one of a knitted material and unwoven cloth.

37. The manufacturing method according to claim 33, wherein the rubber
comprises silicone rubber having a siloxane bond.

Description:

BACKGROUND OF THE INVENTION

[0001]1. Field of the Invention

[0002]The present invention relates to a drum pad for use as an electronic
drum pad or a practice pad, and a manufacturing method of the same.

[0003]2. Description of the Related Art

[0004]Conventionally, a drum pad for use in an electronic drum or the like
has been known, which generally has an elastic pad portion having a
percussion surface, and a base portion provided on a rear side of the pad
portion and mounted with a sensor for detecting the striking of the pad
portion.

[0005]For example, Japanese Laid-open Patent Publication No. 2005-227535
discloses an electronic drum pad, in which an iron plate as a base
portion is fixed to a rear side of a pad portion, a sensor board made of
resin is fixed to a rear surface of the iron plate, and a sensor is fixed
to a rear surface of the sensor board.

[0006]The sensor comprised of a piezoelectric device detects a variation
conveyed from the pad portion being struck to the iron plate and the
sensor board, and outputs a detection signal. Accordingly, the striking
of the pad portion is detected by detecting a vibration of the iron plate
and the sensor board.

[0007]However, a vibration of the base portion formed of the iron plate
does not attenuate immediately. Accordingly, when a trigger for sounding
a drum sound is detected from the detection signal representing a
striking vibration, there is a fear that the trigger is erroneously
detected twice or more while the striking vibration continues and that
the next trigger cannot be detected if the pad portion is struck again
before the preceding striking vibration does not attenuate. Thus, a
problem. is posed that the striking cannot be detected accurately,
resulting in erroneous sounding.

[0008]Aside from electronic sounding, a "bong" mechanical percussion sound
is sometimes produced when the pad portion is struck. The mechanical
percussion sound, if excessively large, causes a problem that musical
performance is hindered.

[0009]Heretofore, it has been demanded for the drum pad for electronic
drum or the like to provide a percussion feeling as close as possible to
that of an acoustic drum pad. To meet the demand, improvement in raw
material of the body portion of the drum pad has been investigated.

[0010]To provide a satisfactory percussion feeling and to perform a proper
percussion detection, the base portion mounted with a percussion
detection sensor must be securely fixed to the body portion of the drum
pad. Usually, the base portion is fixed to the body portion by using an
adhesive.

[0011]However, among raw materials of the body portion that provide a
satisfactory percussion feeling, there are some that do not allow an
adhesive to stick well, and therefore, actually usable materials are
limited. For example, ordinary adhesive does not properly stick to, e.g.,
a silicone-based rubber material. Accordingly, it is difficult to adhere
the base portion having, e.g., a metallic contact surface to the body
portion made of silicone rubber material using adhesive, and therefore, a
double-sided adhesive tape or an adhesive for silicone must be used,
which results in increased cost. In addition, it is difficult to ensure
the required adhesion strength. The above is a bottleneck in using a
silicone-based rubber material as a material of the body portion of the
drum pad.

[0012]In studying a material for the body portion of the drum pad, it is
also necessary to consider how to securely join a front surface material
constituting the percussion surface, etc. to the body portion by using,
e.g., adhesive .

SUMMARY OF THE INVENTION

[0013]The present invention provides a drum pad capable of providing an
excellent percussion feeling and securely adhering a base portion to a
body portion made of rubber, and provides a manufacturing method of the
drum pad.

[0014]The present invention also provides a drum pad capable of
suppressing a mechanical percussion sound and capable of enhancing the
effect of damping a high-frequency vibration caused by the striking,
thereby preventing erroneous sounding when a sound is sounded based on
percussion detection.

[0015]According to a first aspect of this invention, there is provided a
drum pad which includes a body portion made of rubber and having a rear
surface thereof on a side opposite from a side where the drum pad is
struck; a rear-side clothlike material provided on the rear surface of
the body portion; and a fixing layer made of adhesive and provided on a
rear surface of the rear-side clothlike material, wherein the body
portion is joined to a front surface of the rear-side clothlike material
by impregnating the rear-side clothlike material with the rubber of the
body portion.

[0016]With the above drum pad, it is possible to realize an excellent
percussion feeling and to securely adhere a base portion to the rear
surface of the body portion made of rubber.

[0017]The drum pad can include a base portion fixed to the rear surface of
the rear-side clothlike material via the fixing layer.

[0018]With this construction, the drum pad whose base portion is securely
adhered to the rear surface of the body portion made of rubber can be
obtained.

[0019]The drum pad can include a front-side clothlike material having a
rear surface thereof to which the body portion is joined and a front
surface thereof opposite from the rear surface of the front-side
clothlike material, wherein the front-side clothlike material includes a
first layer portion on a side of the front surface of the front-side
clothlike material, the first layer portion formed by intruding a
stretchable resin material into the front-side clothlike material, and a
second layer portion between the first layer portion and the body
portion, the second layer portion being impregnated with the rubber of
the body portion. Both the rear-side clothlike material and the
front-side clothlike material can be one of a knitted material and
unwoven cloth.

[0020]With the above construction, it is possible to prevent a percussion
surface from being contaminated and to maintain the durability.

[0021]The rubber can be foamed rubber.

[0022]In this case, it is possible to effectively obtain a softly bouncy
percussion surface.

[0023]The rubber can be silicone rubber having a siloxane bond.

[0024]In the case, liquid rubber can be used as the rubber material,
making it easy to cast the rubber and making it possible to effectively
manufacture the drum pad which is excellent in rebounding property and
weathering resistance.

[0025]According to a second aspect of this invention, there is provided a
drum pad, which includes a pad portion having a surface thereof adapted
to be struck, and a base portion disposed on a rear side of the pad
portion, wherein the base portion includes first and second metal plates
and a resin layer interposed between the first and second metal plates.

[0026]With the above drum pad, it is possible to suppress a mechanical
percussion sound and to enhance the effect of damping a high-frequency
vibration generated by the striking, thereby making it possible to
prevent erroneous sounding in a case where a sound is sounded based on
percussion detection.

[0027]The drum pad can include a percussion sensor configured to detect a
vibration of the base portion to thereby detect striking of the surface
of the pad portion.

[0028]With the above construction, it is possible to prevent the
percussion sensor from performing erroneous detection, thus making it
possible to prevent a sound from being erroneously sounded.

[0029]The first and second metal plates can each have a thickness in a
range of 0.3 mm to 2.3 mm, and the resin layer can have a thickness equal
to or larger than 0.1 mm.

[0030]With this construction, it is possible to properly ensure the
high-frequency vibration damping effect.

[0031]The resin layer can be thinner than the first metal plate or the
second metal plate, whichever is thinner.

[0032]With this construction, it is possible to reduce waste of resin, to
thereby suppress the cost.

[0033]The first and second metal plates can have a same construction.

[0034]In this case, it is possible to reduce the number of component parts
to thereby simplify the construction.

[0035]According to a third aspect of this invention, there is provided a
drum pad including a body portion made of rubber and having a rear
surface thereof on a side opposite from a side where the drum pad is
struck; a rear-side clothlike material provided on the rear surface of
the body portion; and a base portion having at least a member formed with
holes extending therethrough in a front-rear direction, the base portion
being fixed at a side of the member to a rear surface of the rear-side
clothlike material via a fixing layer made of adhesive, wherein the body
portion is joined to a front surface of the rear-side clothlike material
by impregnating the rear-side clothlike material with the rubber of the
body portion.

[0036]With the above drum pad, an excellent percussion feeling can be
provided, and the base portion can securely be adhered to the rear
surface of the body portion made of rubber.

[0037]The holes can be distributed in a higher density in a region further
away from an outer periphery of the base portion.

[0038]With this construction, venting is much promoted in a region closer
to the center of the base portion, thereby making the adhesion strength
uniform over the entire surface of the base portion.

[0039]The drum pad can include a front-side clothlike material having a
rear surface thereof to which the body portion is joined and a front
surface thereof opposite from the rear surface of the front-side
clothlike material, wherein the front-side clothlike material comprises a
first layer portion on a side of the front surface of the front-side
clothlike material, the first layer portion formed by intruding a
stretchable resin into the front-side clothlike material, and a second
layer portion between the first layer portion and the body portion, the
second layer portion being impregnated with the rubber of the body
portion.

[0040]With the above construction, it is possible to prevent a percussion
surface from being contaminated and to maintain the durability.

[0041]According to a fourth aspect of this invention, there is provided a
manufacturing method of a drum pad including a body portion having a rear
surface thereof on a side opposite from a side where the drum pad is
struck, and a rear-side clothlike material provided on the rear surface
of the body portion. The method includes a disposing step of disposing
the rear-side clothlike material in the mold, a rear surface of the
rear-side clothlike material provided with a fixed layer made of adhesive
and a molding step of casting liquid resin material or thermally-softened
non-vulcanized rubber into a mold, to thereby form the body portion made
of rubber and join the body portion to the front surface of the rear-side
clothlike material by impregnating the rear-side clothlike material with
the liquid resin material or thermally-softened non-vulcanized rubber.

[0042]With the above manufacturing method, it is possible to provide a
drum pad able to realize an excellent percussion feeling and to securely
adhere the base portion to the rear surface of the body portion made of
rubber.

[0043]According to a fifth aspect of this invention, there is provided a
manufacturing method of a drum pad including a front-side clothlike
material that has a front surface thereof on a side where the drum pad is
struck and a rear surface thereof opposite from the front surface, a body
portion having a front surface thereof affixed to the rear surface of the
front-side clothlike material and a rear surface thereof opposite from
the front surface thereof, and a rear-side clothlike material provided on
the rear surface of the body portion. The method includes a thermal
adhesion step of forming a first layer portion in the front-side
clothlike material on a side of the front surface thereof by intruding
the front surface of the front-side clothlike material with a molten
stretchable resin material which is solidified integrally with the
front-side clothlike material; a disposing step of disposing the
front-side clothlike material with the first layer portion in a mold; a
disposing step of disposing the rear-side clothlike material in the mold,
a front surface of the rear-side clothlike material opposite to the rear
surface of the front-side clothlike material, a rear surface of the
rear-side clothlike material provided with a fixing layer of adhesive;
and a molding step of casting liquid resin material or thermally-softened
non-vulcanized rubber into a mold from between the rear surface of the
front-side clothlike material and a front surface of the rear-side
clothlike material to thereby form the body portion made of rubber,
wherein a second layer portion in the front-side clothlike material is
formed by impregnating the front-side clothlike material with the liquid
resin material or thermally-softened non-vulcanized rubber between the
first layer portion of the front-side clothlike material and the body
portion, thereby joining the body portion to the rear surface of the
front-side clothlike material, and wherein the rear-side clothlike
material is impregnated with the liquid resin material or
thermally-softened non-vulcanized rubber, thereby joining the body
portion to the front surface of the rear-side clothlike material.

[0044]With the above manufacturing method, it is possible to provide a
drum pad able to securely adhere a base portion to the rear surface of
the body portion made of rubber, to prevent a percussion surface from
being contaminated, and to maintain the durability. In addition, since
processing on the front side and processing on the rear side can be
performed concurrently in one molding process, it is possible to simplify
the process of fabrication.

[0045]According to a sixth aspect of this invention, there is provided a
manufacturing method of a drum pad including a body portion having a rear
surface thereof on a side opposite from a side where the drum pad is
struck, and a rear-side clothlike material provided on the rear surface
of the body portion. The method includes a disposing step of disposing in
a mold a rear-side clothlike material with a rear surface affixed to a
base portion via a fixing layer made of adhesive, the base portion
comprising at least a member formed with holes extending therethrough in
a front-rear direction; and a molding step of casting liquid resin
material or thermally-softened non-vulcanized rubber into a mold from the
side close to the front surface of the rear-side clothlike material, to
thereby form the body portion made of rubber and join the body portion to
the front surface of the rear-side clothlike material by impregnating the
rear-side clothlike material with the liquid resin material or
thermally-softened non-vulcanized rubber.

[0046]With the above manufacturing method, it is possible to provide a
drum pad able to realize an excellent percussion feeling and to securely
adhere the base portion to the rear surface of the pad portion made of
rubber.

[0047]According to a seventh aspect of this invention, there is provided a
manufacturing method of a drum pad including a front-side clothlike
material that has a front surface thereof on a side where the drum pad is
struck and a rear surface thereof opposite from the front surface, a body
portion having a front surface thereof affixed to the rear surface of the
front-side clothlike material and a rear surface thereof opposite from
the front surface thereof, and a rear-side clothlike material provided on
the rear surface of the body portion. The method includes a thermal
adhesion step of forming a first layer portion in the front-side
clothlike material on a side of the front surface thereof by intruding
the front surface of the front-side clothlike material with a molten
stretchable resin material which is solidified integrally with the
front-side clothlike material; a disposing step of disposing the
front-side clothlike material with the first layer portion in a mold; a
disposing step of disposing in a mold the rear-side clothlike material in
a mold, a front surface of the rear-side clothlike material opposite to
the rear surface of the front-side clothlike material, the rear-side
cloth material with a rear surface affixed to a base portion via a fixing
layer made of adhesive, the base portion comprising at least a member
formed with holes extending therethrough in a front-rear direction; and a
molding step of casting liquid resin material or thermally-softened
non-vulcanized rubber into a mold from between the rear surface of the
front-side clothlike material and a front surface of the rear-side
clothlike material, to thereby form the body portion made of rubber,
wherein a second layer portion in the front-side clothlike material is
formed by impregnating the front-side clothlike material with the liquid
resin material or thermally-softened non-vulcanized rubber between the
first layer portion of the front-side clothlike material and the body
portion, thereby joining the body portion to the rear surface of the
front-side clothlike material, and wherein the rear-side clothlike
material is impregnated with the liquid resin material or
thermally-softened non-vulcanized rubber, thereby joining the body
portion to the front surface of the rear-side clothlike material.

[0048]With the above manufacturing method, it is possible to provide a
drum pad able to realize an excellent percussion feeling, to securely
adhere the base portion to the rear surface of the body portion made of
rubber, to prevent a percussion surface from being contaminated, and to
maintain the durability. In addition, since processing on the front side
and processing on the rear side can be carried out concurrently in one
molding process, it is possible to simplify the process of fabrication.

[0049]Further features of the present invention will become apparent from
the following description of an exemplary embodiment with reference to
the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0050]FIG. 1A is a perspective view schematically showing a drum pad
according to one embodiment of this invention;

[0051]FIG. 1B is a section view of the drum pad;

[0052]FIG. 2A is a section view of a resin material used for production of
the drum pad;

[0053]FIG. 2B is a section view of a front-side clothlike material used
for production of the drum pad;

[0054]FIG. 2C is a section view of a temporary composite layer
corresponding to a front-side composite layer of the drum pad;

[0055]FIG. 2D is a section view of a separate paper-equipped composite
layer used for production of the drum pad;

[0061]FIGS. 6A and 6B are views showing modifications of the molding
process of the drum pad;

[0062]FIG. 7A is a section view schematically showing the construction of
a drum pad having abase portion formed with vent holes; and

[0063]FIG. 7B is a view showing a molding process of the drum pad shown in
FIG. 7A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0064]The present invention will now be described in detail below with
reference to the drawings showing a preferred embodiment thereof.

[0065]FIG. 1A schematically shows in perspective view a drum pad according
to one embodiment of this invention. The drum pad shown at 10 in FIG. 1A
is for use as, e.g., an electronic drum pad or a percussion input device
for receiving percussion data to obtain sounding data, the drum pad 10
being adapted to be struck by a stick 11 or the like. The drum pad 10 is
not, however, limited to these examples, and may be a pad for use as
percussion practice, which is singly laid on a table or the like when
used. The drum pad 10 is formed into, e.g., a disk-shape having a
diameter φ of 260 mm and a thickness t of 20 mm for use in a 10 or 12
inch snare drum or tom although the shape, size, and intended use of the
drum pad 10 are not limited thereto.

[0066]FIG. 1B schematically shows the construction of the drum pad 10 in
cross section. For convenience of explanation, it is assumed that the
drum pad 10 is disposed to be horizontal as shown in FIG. 1B although the
orientation of the drum pad 10 at the time of performance is not limited.
In the following, the upper and lower sides in the drawings will be
referred to as the front and rear sides, respectively. Some parts of the
drum pad 10 are illustrated with exaggerated thicknesses and with a scale
different from actual one.

[0067]As shown in FIG. 1B, the drum. pad 10 is comprised of a pad portion
15, a rear-side composite layer 30M2, and a base portion 40, which are
stacked in this order from above. The pad portion 15 is comprised of a
body portion 14 and a front-side composite layer 20M2 formed on an upper
surface 14a of the body portion 14. The composite layer 20M2 is comprised
of first and second layer portions 21, 22M2, which are vertically
separated at a boundary portion 23. In the front-side composite layer
20M2, the entire region other than the first layer portion 21 is occupied
by the second layer portion 22M2.

[0068]The front-side composite layer 20M2 has a front surface 20Ma (which
is an upper surface, i.e., a percussion surface 10a, of the drum pad 10)
and a rear surface 20Mb joined to an upper surface 14a of the body
portion 14. The surfaces 20Ma, 20Mb are each formed to be flat, and the
boundary portion 23 can be formed to be flat or non-flat.

[0069]The rear-side composite layer 30M2 is comprised of a rear-side
clothlike material 32M2 and a pressure sensitive adhesive 31 applied to a
rear surface 32b of the clothlike material 32M2 whose front surface 32a
is joined to a lower surface 14b of the body portion 14.

[0070]The base portion 40, which is provided on the lower side of the
rear-side composite layer 30M2, has a three-layer structure comprised of
a front-side first metal plate 41, a rear-side second metal plate 42, and
a resin layer 43 interposed between the metal plates 41, 42. The base
portion 40 is adhered at its upper surface 40a (which is an upper surface
of the first metal plate 41) to a rear surface 32b of the clothlike
material 32M2 by the pressure sensitive adhesive 31.

[0071]A percussion sensor 19 is fixed to near the center of a lower
surface 40b of the base portion 40 (which is a lower surface of the
second metal plate 42). The percussion sensor 19 has a piezoelectric
device for converting a vibration of the base portion 40 into an
electrical signal representing whether the drum pad 10 is struck and the
intensity of striking. It should be noted that the percussion sensor 19
can have any construction and can be disposed at any position so long as
it can detect the striking in terms of vibration. When the percussion
surface 10a of the drum pad 10 is struck, the base portion 40 vibrates
and the vibration is detected by the percussion sensor 19. A trigger can
be detected from a detection signal output from the sensor 19, and a drum
sound can be generated by a musical tone generator (not shown).

[0072]FIGS. 2A and 2B show in cross section respective ones of a resin
material 12 and a front-side clothlike material 20, which are used for
production of the drum pad 10. FIG. 2C shows in cross section a temporary
composite layer corresponding to the front-side composite layer 20M2 of
the drum pad 10.

[0073]In a raw material stage, the pad portion 15 is comprised of a resin
material 12, a front-side clothlike material 20, and a rubber material 13
(see FIG. 3A). The rubber material 13 is a molding material for the body
portion 14. The resin material 12 and the clothlike material 20 are much
thinner than the body portion 14, and the resin material 12 is thinner
than the clothlike material 20.

[0074]As the front-side clothlike material 20 (see FIG. 2B), a material
stretchable in any two-dimensional direction (2-way stretchable), e.g., a
knitted material, is used, but unwoven cloth may be used. By using either
of these materials, a direction in which the stick 11 is rebounded
becomes similar to that in an acoustic drum pad.

[0075]The knitted material here represents a knitted cloth or other cloth
in which looped yarns are laterally or vertically coupled together. The
unwoven cloth represents a cloth in which fibers are coupled together
without being woven or knitted. For the unwoven cloth, the kind of fibers
is not limited, and natural fibers or synthetic fibers may be used.

[0076]As the resin material 12 (see FIG. 2A), a stretchable film-like
resin material capable of being thermally fused and bonded to the
front-side clothlike material 20 is used. For example, polyolefin is
used. Alternatively, polyurethane resin, mixture of polyurethane and
polyester, or mixture of polyurethane and nylon may be employed.

[0078]As described later, when the rubber material 13 is formed into the
body portion 14, a temporary second layer portion 22M1 of a temporary
composite layer 20M1 shown in FIG. 2C is impregnated with the rubber
material 13 to become the second layer portion 22M2 shown in FIG. 1B.

[0079]FIG. 2D shows in cross section a separate paper-equipped composite
layer, which is used for production of the drum pad 10. The separate
paper-equipped composite layer 35 is comprised of a temporary composite
layer 30M1 and a separate paper 33. The layer 30M1 is comprised of a
temporary rear-side clothlike material 32M1 and the pressure sensitive
adhesive 31 applied to a lower surface of the clothlike material 32M1.
The separate paper 33 is affixed to a rear surface of the adhesive 31. As
described later, when the rubber material 13 is formed into the body
portion 14, the clothlike material 32M1 shown in FIG. 2D is impregnated
with the rubber material 13 to become the rear-side clothlike material
32M2 shown in FIG. 1B.

[0080]As with the front-side clothlike material 20 (see FIG. 2B), a
knitted material is used as a raw material of the temporary rear-side
clothlike material 32M1. Alternatively, unwoven cloth, or a combination
of knitted material for the front-side clothlike material 20 and unwoven
cloth for the temporary rear-side clothlike material 32M1, or the reverse
combination may be used. It should be noted that felt or other cloth than
knitted material or unwoven cloth may be used for the clothlike material
32M1 which is not required to have stretchability.

[0081]As the pressure sensitive adhesive 31, e.g., acrylic adhesive is
suitable, but adhesive having a good adhesion to the first metal plate 41
may be used, such as rubber-based adhesive, silicone-based adhesive, or
hot melt, which is selected according to a material of the first metal
plate 41.

[0082]FIG. 2E shows the base portion 40 in cross section. As previously
described, the base portion 40 is comprised of the first and second metal
plates 41, 42 and the resin layer 43 interposed therebetween. The metal
plates 41, 42 which are the same in construction each have a thickness of
tl and are each made of an ordinary steel plate of aluminum, stainless,
or iron. The resin layer 43 has a thickness of t2 and is made of, e.g.,
vinyl chloride resin or acrylate resin although not limitative thereto.
To fix the metal plates 41, 42 and the resin layer 43 together, the resin
layer 43 formed into, e.g., a sheet is affixed to the metal plates 41, 42
using a pressure sensitive adhesive double coated tape or the like.

[0083]The base portion 40 is configured as a laminated damping steel sheet
that has an excellent vibration damping effect, especially, an excellent
high-frequency vibration damping effect, which is attained by the
three-layer structure having the resin layer 43 interposed between the
metal plates 41, 42. To enable the base portion 40 to exhibit the
required vibration damping effect and to suppress the cost, the thickness
tl of the metal plates 41, 42 is set in a range of 0.3 mm to 2.3 mm
(e.g., at 0.8 mm) and the thickness t2 of the resin layer 43 is set in a
range of 0.1 mm to 0.5 mm (e.g., at 0.5 mm).

[0084]The reason why the thickness tl of the metal plates 41, 42 is
selected to be in the above range is to enable the base portion 40
properly vibrates when the percussion surface 10a is struck. The reason
why the thickness t2 of the resin layer 43 is selected to be in the above
range is as follows: If the thickness t2 is made less than 0.1 mm, the
vibration damping effect becomes small, and if excessively thinned, the
resin layer 43 is hard to be fabricated. On the other hand, even if the
thickness t2 is made thicker than 0.5 mm, the vibration damping effect is
not further improved. If the resin layer 43 is excessively thickened,
resin material is wasted. Since the vibration damping effect is exhibited
even if the resin layer 43 has a thickness thicker than 0.5 mm, it is not
inevitably necessary to limit the thickness t2 to a value not greater
than 0.5 mm.

[0085]To reduce the waste of resin in order to suppress the cost, the
thickness t2 of the resin layer 43 is preferably made thinner than the
thickness tl of the metal plates 41, 42. It should be noted that it is
not inevitably necessary to configure the metal plates 41, 42 to have the
same thickness so long as their thicknesses are in the above range. In
that case, preferably, the resin layer 43 is made thinner than the first
metal plate 41 or the second metal plate 42, whichever is thinner.

[0086]Next, a manufacturing method of the drum pad 10 will be described
with reference to FIGS. 2A to 2D and FIG. 3A.

[0087]FIG. 3A illustrates in cross section a molding process of the drum
pad 10 except for the base portion 40.

[0088]First, the resin material 12, the front-side clothlike material 20,
and the separate paper-equipped composite layer 35 are prepared (see
FIGS. 2A, 2B, and 2D), each of which is formed to have a predetermined
shape (e.g., circular shape) and a predetermined thickness. The resin
material 12 has a thickness of about 0.1 mm, and the front-side clothlike
material 20 has a thickness of about 0.2 mm. It should be noted that the
resin material 12, the clothlike material 20, and the composite layer 35
may be cut later in a circular shape along with the body portion 14 after
the body portion 14 is molded.

[0089]Then, the resin material 12 (see FIG. 2A) is thermally fused and
bonded at the rear surface 12b to the front surface 20a of the front-side
clothlike material 20. This is accomplished by, e.g., causing the resin
material 12 and the clothlike material 20, which are laid overlap each
other, to pass through two heated rollers.

[0090]It is assumed here that the melting point of the resin material 12
is lower than that of the front-side clothlike material 20, and the resin
material 12 is thinner than the clothlike material 20. Accordingly, when
the resin material 12 and the clothlike material 20 which are
overlappingly laid are fused and bonded at a temperature at which the
resin material 12 melts, the molten resin material 12 intrudes, as shown
in FIG. 2C, into a region on the front side of the front-side clothlike
material 20. The region extends from the front surface 20a of the
clothlike material 20 to the boundary portion 23 and corresponds to the
thickness of the resin material 12. When the front-side clothlike
material 20 is cooled in this state, a first layer portion 21 is formed
in the front-side region of the clothlike material 20 into which the
resin material 12 has intruded. In the first layer portion 21, the resin
material 12 has solidified and has been made integral with an upper half
of the clothlike material 20. On the other hand, the remaining region of
the clothlike material 20 (extending from the boundary portion 23 to the
rear surface 20b) other than the first layer portion 21 becomes the
temporary second layer portion 22M1 formed of only the knitted material.

[0091]In the resultant temporary composite layer 20M1, the front surface
20a of the front-side clothlike material 20 forms a front surface 20Ma of
the first layer portion 21, and the rear surface 20b of the clothlike
material 20 forms a rear surface 20Mb of the temporary composite layer
20M1.

[0092]Next, as shown in FIG. 3A, the separate paper-equipped composite
layer 35 is disposed at the bottom of a mold 24 such that the temporary
rear-side clothlike material 32M1 is positioned upward of the pressure
sensitive adhesive 31 and the separate paper 33, and the temporary
composite layer 20M1 is disposed on the ceiling side in the mold 24 such
that the temporary second layer portion 22M1 is positioned downward of
the first layer portion 21. Then, the rubber material 13 is cast between
the separate paper-equipped composite layer 35 and the temporary
composite layer 20M1, thereby molding the body portion 14.

[0093]Specifically, liquid material A and liquid material B as two-liquid
type RTV rubber are weighed and mixed well. Then, the mixture of
materials A and B is cast into the mold 24, and the mixture is foamed and
solidified at a room temperature after the mold 24 is closed. A space S1
initially present in the mold 24 on the side close to the rear surface
20Mb of the temporary composite layer 20M1 is gradually filled with the
foamed rubber material 13.

[0094]During the rubber material 13 is foamed, the rubber material 13 is
impregnated into the temporary rear-side clothlike material 32M1 of the
temporary composite layer 30M1 from above. The impregnation stops at a
boundary between the clothlike material 32M1 and the pressure sensitive
adhesive 31. When reaching the temporary composite layer 20M1, the rubber
material 13 is impregnated into the temporary composite layer 20M1 from
the rear surface 20Mb thereof. Since the first layer portion 21 of the
temporary composite layer 20M1 is already impregnated with the resin
material 12, the rubber material 13 is not impregnated into the first
layer portion 21 and the impregnation stops at the boundary portion 23.
In other words, the first layer portion 21 serves as a stopper for
preventing the rubber material 13 from impregnating into a region of the
temporary composite layer 20M1 on the front surface 20Ma side.
Subsequently, annealing is performed.

[0095]As a result, the foamed and solidified rubber material 13 forms the
body portion 14 (see FIG. 1B). On the side upward of the body portion 14,
the temporary second layer portion 22M1 becomes the second layer portion
22M2 impregnated with the rubber material 13. As shown in FIG. 1B, the
first and second layer portions 21 and 22M2 form the front-side composite
layer 20M2, which is bonded at its rear surface 20Mb to the upper surface
14a of the body portion 14, whereby the pad portion 15 is formed.

[0096]On the side downward of the body portion 14, the temporary rear-side
clothlike material 32M1 becomes the rear-side clothlike material 32M2
impregnated with the rubber material 13 (see FIG. 1B). The clothlike
material 32M2 and the pressure sensitive adhesive 31 form the rear-side
composite layer 30M2. The rear-side clothlike material 32M2 is bonded at
its front surface 32a to the lower surface 14b of the body portion 14.

[0097]The second layer portion 22M2 and the rear-side clothlike material
32M2 each impregnated with the rubber material 13 are each joined to the
body portion 14. In each joining area, fibers of the knitted cloth or the
unwoven cloth forming the layer portion 22M2 (or the clothlike material
32M2) extend across the body portion 14 and the layer portion 22M2 (or
the clothlike material 32M2). Therefore, the bonding strength is high. In
addition, since an adhesive agent for the bonding is unnecessary, the
manufacturing process is simplified. It should be noted that the
configuration and orientation of the mold 24 are not limited to those of
the illustrated example.

[0098]FIG. 3B schematically shows the front-side composite layer 20M2.
Since fibers (one of which is shown at 20c) of the front-side clothlike
material 20 intrude into and are anchored to the first and second layer
portions 21, 2 2M2 , these fibers serve as abridge that binds the two
layer portions 21, 22M2 together, to thereby accomplish the
reinforcement. Thus, the first layer portion 21 is hardly separated from
the second layer portion 22M2, and both the layer portions are fibered
and reinforced. In a case where the front-side clothlike material 20 is
formed of either knitted cloth or unwoven cloth, the layer portions 21,
22M2 are hardly torn or broken when the pad is struck.

[0099]The body portion 14 joined at its front and rear surfaces with the
front-side and rear-side composite layers 20M2, 30M2 is taken out from
the mold 24. Thereafter, the base portion 40 separately fabricated is
attached to the body portion 14. Specifically, the separate paper 33
affixed to the composite layer 30M2 is removed to thereby expose the
pressure sensitive adhesive 31, and the base portion 40 is affixed or
adhered at its upper surface 40a (upper surface of the first metal plate
41) to the exposed adhesive 31, whereby the base portion 40 is fixed to
the rear surface 32b of the rear-side clothlike material 32M2, and the
drum pad 10 is completed.

[0100]Since the resin material 12 has stretchability and the front-side
clothlike material 20 has two-way stretchability, high stretchability can
be obtained. Accordingly, when the percussion surface 10a is struck, a
struck portion thereof is locally deformed and produces a large
resiliency. As a result, a percussion feeling is not hard and the stick
11 rebounds well.

[0101]As previously described, the base portion 40 of this embodiment has
the enhanced vibration damping effect by the three-layer structure. In
the following, the vibration damping effect of the three-layer structure
is compared with those of other structures than the three-layer
structure. Hereinafter, the three-layer structured base portion (i.e.,
the base portion 40) will be referred to as the constrained type, a base
portion comprised of only the first metal plate 41 and the resin layer 43
provided on the rear side of the metal plate 41 (i.e., a base portion
where the second metal plate 42 is removed from the base portion 40) will
be referred to as the unconstrained type, and a base portion comprised of
only the first metal plate 41 (i.e., a base portion where the resin layer
43 and the second metal plate 42 are removed from the base portion 40 so
that the vibration damping function is eliminated) will be referred to as
the non-damping type.

[0102]FIG. 4A to FIG. 4C respectively show damping times of vibration
acceleration of the base portions of non-damping, unconstrained, and
constrained types, where elapsed time (second) from when each base
portion is struck is taken along the abscissa and vibration acceleration
(m/sec2) is taken along the ordinate. FIG. 5A to FIG. 5C
respectively show relations between vibration amplitude and vibration
frequency of the base portions of non-damping, unconstrained, and
constrained types, where vibration amplitude (dB) is taken along the
abscissa and vibration frequency (Hz) is taken along the ordinate.

[0103]In actual measurements of the vibration acceleration and vibration
amplitude-frequency characteristic of each base portion, an acceleration
pickup was disposed at the center of a rear surface of the base portion,
and the center of a percussion surface was struck by a predetermined
load. An electrolytic zinc-plated steel sheet (SECC) was used as the
first and second metal plates 41 and 42, and vinyl chloride was used as
the resin layer 43.

[0104]The actually measured vibration acceleration of each base portion
represents the magnitude of vertical displacement of the base portion,
which provides a measure of vibration intensity or vibration energy. As
understood from FIGS. 4A to 4C, the vibration of the base portion of
non-damping type was not damped immediately and continued even after
elapse of 0.2 seconds from the striking, the vibration of the
unconstrained type was damped somewhat rapidly and nearly damped at the
elapsed time of 0.2 seconds, and the vibration of the constrained type
was damped rapidly and damped to nearly zero at the elapsed time of 0.02
seconds . To attain the desired vibration containing less noise
components and to attain a large damping effect, it is the to be
preferable that the vibration of the base portion be damped to nearly
zero within the elapsed time of 0.1 seconds. The constrained type
sufficiently satisfies such requirement.

[0105]To attain the desired vibration damping effect, the damping effect
in a high-frequency range, especially, in a frequency range of 80 Hz to
350 Hz, is important . In the case of the non-damping type, a highly
sharp resonance crest appears at a frequency of near 100 Hz and resonance
crests appear in a frequency range of 200 Hz to 350 Hz, as shown in FIG.
5A. In the case of the unconstrained type as shown in FIG. 5B, similar
resonance crests are found, but the sharpness of the crests is slightly
moderated. In the case of the constrained type as shown in FIG. 5C, no
resonance crest is found in a high-frequency range although a low
resonance crest is found at a frequency range of less than 80 Hz, which
does not affect the sounding of a percussion sound. Thus, an excellent
damping effect is recognized.

[0106]According to this embodiment, the resin material 12 is thermally
fused and bonded to the front-side clothlike material 20 to thereby
obtain the temporary composite layer 20M1, and the rubber material 13 is
foamed and solidified between the separate paper-equipped composite layer
35 and the temporary composite layer 20M1, thereby molding the body
portion 14.

[0107]In the drum pad 10 which is in a preparatory stage and to which the
base portion 40 is subsequently adhered, the rubber material 13 has been
impregnated into the rear-side clothlike material 32M2 made of knitted
material, the body portion 14 has been joined to the front surface 32a of
the rear-side clothlike material 32M2, and the pressure sensitive
adhesive 31 has been applied to the rear surface 32b of the rear-side
clothlike material 32M2.

[0108]Accordingly, it is possible to stick the pressure sensitive adhesive
31 to the body portion 14 via the rear-side clothlike material 32M2, even
if the adhesive 31 is non-special adhesive that cannot directly be stuck
to the body portion 14 made of rubber material 13. Thus, by using the
pressure sensitive adhesive 31, the base portion 40 having a metallic
adhered surface can securely be adhered to the rear surface of the pad
portion 15 made of rubber (i.e., to the lower surface 14b of the body
portion 14). In addition, the body portion 14 formed by the rubber
material 13 of silicone rubber has a large rebound coefficient and
provides a satisfactory percussion feeling.

[0109]Since the front-side composite layer 20M2 is formed by the first
layer portion 21 intruded with the resin material 12 and by the second
layer portion 22M2 impregnated with the rubber material 13 and since the
front-side composite layer 20M2 is basically formed of knitted material
or the like, the stick 11 is rebounded in a direction similar to that in
an acoustic drum, and therefore, a natural percussion feeling can be
realized. In addition, since the percussion surface 10a is provided by
the first layer portion 21 in which the resin material 12 is intruded and
solidified, it is possible to improve the quietness and enhance the
impact strength. Besides, since the knitted material is protected by the
resin material 12, a large effect of preventing contamination can be
attained. It is therefore possible to prevent the percussion surface 10a
from being contaminated, to maintain the durability of the percussion
surface 10a, and to achieve a natural excellent percussion feeling.

[0110]Since the rubber material 13 can be impregnated into the temporary
rear-side clothlike material 32M1 and into the temporary second layer
portion 22M1 in one molding process, processing on the front side and
processing on the rear side can be performed concurrently, whereby the
fabrication process can be simplified. It should be noted that the rubber
material 13 can be foamed in two stages so as to separately perform a
process for impregnating the rubber material 13 into the clothlike
material 32M1 and a process for impregnating the rubber material 13 into
the layer portion 22M1.

[0111]When the rubber material 13 formed of silicone rubber having a
siloxan bond is used, liquid rubber can be used as the rubber material 13
that can easily be cast into the mold and that is effective to fabricate
a drum pad which is excellent in resiliency and weather resistance. The
rubber material 13 formed of foamed rubber is effective to fabricate a
softly bouncy percussion surface.

[0112]According to this embodiment, since the base portion 40 provided on
the rear side of the pad portion 15 (i.e., on the lower surface 14b of
the body portion 14) and mounted with the percussion sensor 19 has the
three-layer structure in which the resin layer 43 is disposed between the
first and second metal plates 41 and 42, it is possible to suppress a
mechanical percussion sound and enhance the effect of damping a
high-frequency vibration produced by the striking, making it possible to
prevent an error when producing a sound based on percussion detection.
The resultant vibration contains less noise components and is uniform in
amplitude over a wide frequency range.

[0113]Since the thickness t1 of the metal plates 41, 42 is set in a range
of 0.3 mm to 2.3 mm and the thickness t2 of the resin layer 43 is set in
a range of 0.1 mm to 0.5 mm, it is possible to attain a proper damping
effect in a high-frequency region, while suppressing the cost.

[0114]Since the metal plates 41, 42 have the same construction, it is
possible to reduce the number of component parts and to simplify the
construction.

[0115]In this embodiment, on the rear surface 32b of the rear-side
clothlike material 32M2 (i.e., on the lower surface of the temporary
rear-side clothlike material 32M1), there is provided a fixing layer
formed of the pressure sensitive adhesive 31, but the fixing layer is not
limited thereto. For example, the fixing layer can be formed by an
adhesive. In that case, e.g., an adhesive film of hot melt type can be
intruded, fused, and bonded to a lower half region of the clothlike
material 32M1, and can be fused and bonded to the body portion 14 before
or after the base portion 40 is molded. Alternatively, it is possible to
apply a liquid adhesive agent to the base portion 40, to place the
clothlike material 32M1 on a surface of the base portion 40 to which the
liquid adhesive agent has been applied to thereby cause the liquid
adhesive agent to intrude into a lower half region of the clothlike
material 32M1, and to solidify the liquid adhesive agent so as to be
integral with the clothlike material 32M1. Thereafter, the body portion
14 is molded so that the rubber material 13 is intruded into clothlike
material 32M1 and made integral therewith.

[0116]In this embodiment, the body portion 14 is formed of the rubber
material 13 in order to improve a percussion feeling and weather
resistance. Although it is generally difficult to adhere an urethane film
or metal to silicone-based rubber, this embodiment makes it possible to
join silicone-based rubber to the body portion 14 via the front-side and
rear-side clothlike materials 20, 32M2 formed of a knitted material or
the like, whereby silicone-based rubber can easily be used.

[0117]A fixing technique using impregnation of the rubber material 13
makes it possible to easily combine a laminated damping steel sheet of a
multi-layered structure (such as the base portion 40) and a pad portion
formed of silicone based-rubber although silicone-based rubber cannot
heretofore be used for the base portion 40 since the silicone-based
rubber is hard to stick to the base portion 40, which has the metal
plates 41, 42 and is heavy in weight .

[0118]It is considered that the impregnation speed of the rubber material
13 into the front-side clothlike material 20 varies from location to
location. On this point, the first layer portion 21 of this embodiment
has a function of stopping the impregnation of the rubber material 13 at
the boundary portion 23, whereby a fear of causing a variation in
impregnation region can be eliminated, making it possible to attain the
percussion surface 10a which is smooth and uniform in characteristic.

[0119]The method of molding the drum pad 10 using a mold is not limited to
the above-described method.

[0120]For example, as in a modification shown in FIG. 6A, a positional
relation between the separate paper-equipped composite layer 35 and the
temporary composite layer 20M1 in the mold 24 can be turned upside down
as compared with that in the above-described example.

[0121]Although the separate paper-equipped composite layer 35 is set at
the bottom of the mold 24 in the molding process shown in FIG. 3A, the
temporary composite layer 30M1 adhered in advance with the base portion
40 can be set in the mold 24 as shown in FIG. 6B. In that case, the
composite layer 35 from which the separate paper 33 has been peeled off
and to which the base portion 40 has been adhered is set at the bottom of
the mold 24. Then, the drum pad 10 is molded as previously described.

[0122]It should be noted that there are various modifications of a raw
material of the rubber material 13. Although foamed rubber is used as the
rubber material 13 in the embodiment, non-foamed rubber can be used. For
example, non-foamed silicone rubber formed by not foaming but solidifying
liquid silicone or non-foamed urethane resin formed by not foaming but
solidifying liquid urethane resin can be used.

[0123]In this modification, e.g., the molding process shown in FIG. 6A is
performed by using the mold 24 having a lid mold and a lower mold (none
of which are shown). Specifically, the rubber material 13 (non-foamed
resin) is cast between the separate paper-equipped composite layer 35 and
the temporary composite layer 20M1, and all of these (i.e., the composite
layer 20M1, rubber material 13, and the composite layer 35) is
pressurized, heated, and then solidified. As a result, the body portion
14 is molded and the entire shape is defined by the mold 24. An excessive
of the rubber material 13 is overflown from a gap between the lower mold
and the lid mold.

[0124]Instead of using liquid resin as the rubber material 13, a
non-vulcanized rubber compound may be used. In this modification, there
can be used as raw materials of the rubber material 13, e.g., rubber
materials mainly including NR (natural rubber) and BR (butadiene rubber)
whose mixture ratio is that: 40 parts of NR, 60 parts of BR, and the
remaining parts of additive materials including 3 parts of zinc oxide, 1
part of stearic acid, 6 parts of sulfur, 15 parts of calcium carbonate,
and 10 parts of carbon. These are kneaded by the use of a roll to produce
the rubber material 13 formed of the compound.

[0125]Next, e.g., the molding process shown in FIG. 6A is performed by
using the mold 24 . Specifically, the rubber material 13 (non-vulcanized
rubber compound) is placed on the temporary composite layer 20M1, and the
separate paper-equipped composite layer 35 is laid over the rubber
material 13. Then, all of these (i.e., the temporary composite layer
20M1, rubber material 13, and composite layer 35) is pressurized and
heated at 160 degree C. for 10 minutes. The rubber material 13 is first
softened and impregnated into the temporary rear-side clothlike material
32M1 and into the temporary second layer portion 22M1. As a result, the
clothlike material 32M1 and the layer portion 22M1 become the rear-side
clothlike material 32M2 and the second layer portion 22M2 (which are
shown in FIG. 1B), respectively. A part of the rubber material 13 is
overflown from a gap between the lower mold and the lid mold of the mold
24. The vulcanization is performed to obtain the body portion 14 formed
of elastic rubber.

[0126]To produce the rubber material 13 formed of the compound in the
just-mentioned modification, 4 parts of a foaming agent (for example,
4,4'-oxybis benzene sulfonyl hydralazide whose decomposition temperature
is 160 degrees C.) can be further added, as an additive material.

[0127]In that case, as described in the modification, the temporary
composite layer 20M1, the rubber material 13, and the separate
paper-equipped composite layer 35 are disposed in the mold 24, and then
pressurized and heated. The rubber material 13 is first softened and
impregnated into the temporary rear-side clothlike material 32M1 and the
temporary second layer portion 22M1, whereupon the clothlike material
32M1 and the layer portion 22M1 become the rear-side clothlike material
32M2 and the second layer portion 22M2 (which are shown in FIG. 1B),
respectively. Thereafter, the softened rubber material starts foaming and
vulcanization starts at the same time, and therefore, the pressure of the
mold is gradually decreased. Then, the softened rubber material expands
due to the foaming pressure and fills the space S1 in the mold 24,
thereby obtaining the body portion 14.

[0128]Also in these modifications, the vertical positional relation
between the separate paper-equipped composite layer 35 and the temporary
composite layer 20M1 in the mold 24 is not limited, and the base portion
40 can be adhered in advance to the temporary composite layer 30M1 before
the start of the molding process.

[0129]As described in the embodiment, the raw material of the body portion
14 is not limited to foamy silicone rubber, but may be non-silicone
rubber or non-foamy rubber. Examples of the usable foamy rubber include
urethane rubber, natural rubber, and butadiene rubber. Examples of the
usable non-foamy rubber include silicone rubber, urethane rubber, natural
rubber, and butadiene rubber.

[0130]The base portion 40 is not limited to one having the three-layer
structure, but may have a structure of four or more layers, where a metal
plate is disposed on the uppermost side and metal plates and resin layers
are alternately stacked. For example, the base portion 40 has a
five-layer structure where the first metal plate 41, resin layer 43,
second metal plate 42, resin layer 43, and first metal plate 41 are
stacked in this order from above. It should be noted that in the base
portion 40, acryl plates or the like can be used instead of the metal
plates.

[0131]It is not inevitably necessary to dispose the percussion sensor 19
on the lower surface 40b of the base portion 40. The percussion sensor 19
can be disposed, e.g., at a location on the base portion 40 other than
the lower surface 40b, or inside the body portion 14, or between the body
portion 14 and the base portion 40.

[0132]As previously described, the two-liquid type RTV rubber is used as
the rubber material 13. In the process where the mixture of liquid
materials A and B for the two-liquid type RTV rubber is formed and
solidified in the mold 24 and impregnated into the temporary rear-side
clothlike material 32M1 and the temporary second layer portion 22M1,
gases (e.g., hydrogen gases) are generated by a chemical reaction between
the liquid materials A and B. It is assumed here that the temporary
composite layer 30M1 and the base portion 40 adhered in advance to the
composite layer 30M1 are set at the bottom of the mold 24 as shown in
FIG. 6B and the base portion 40 is insert-molded. In that case, the
generated gases are able to escape laterally via the temporary second
layer portion 22M1 and the temporary rear-side clothlike material 32M1.

[0133]However, since the first metal plate 41 of the base portion 40 does
not permit gases to pass therethough, the generated gases present in a
region near the center of the first metal plate 41 cannot escape
laterally and accumulate therein, resulting in a problem that the first
metal plate 41 at the center region is liable to be peeled off from the
temporary composite layer 30M1.

[0134]To obviate this, it is preferable that vent holes that allow gases
generated in the molding process to escape therethrough be formed in the
first metal plate 41 of the base portion 40, as will be described with
reference to FIGS. 7A and 7B.

[0135]FIG. 7A schematically show in cross section the construction of the
drum pad 10 having the base portion 40 formed with vent holes, and FIG.
7B shows a process for molding the drum pad 10 shown in FIG. 7A.

[0136]As shown in FIG. 7A, a number of vent holes 41a are formed in the
first metal plate 41 of the base portion 40 so as to extend therethrough
in a front-rear direction (vertical direction). The vent holes 41a each
have a diameter of, e.g., 1.6 mm. The vent holes 41a are arranged to have
a higher density in a region much away from an outer periphery 41b of the
first metal plate 41. In other words, a larger number of vent holes 41a
are formed in a region closer to the center of the first metal plate 41.
As a result, the generated gases are able to easily escape from the
center region of the first metal plate 41 via the vent holes 41a.

[0137]The vent holes 41a can have any size that enables the generated
gases to escape therethrough. The size of the vent holes 41a can be
determined by taking into account of the ease of hole formation. For
example, in the case of being formed by press working, it is preferable
that the vent holes 41a have a diameter of 1.6 mm, but can have a
diameter of less than 1.6 mm. If the vent holes 41a has a sufficient
total area, the density in which the vent holes 41a are formed becomes
somewhat insignificant, and hence the vent holes 41a can be formed at
equal intervals of, e.g., 40 mm. The vent holes 41a can be formed by any
method. For example, the vent holes can be formed using a drill.

[0138]In the molding, the first metal plate 41 formed with the vent holes
41a is first adhered at its upper surface to the lower surface of the
temporary rear-side clothlike material 32M1 by the pressure sensitive
adhesive 31. Next, the first metal plate 41 and the clothlike material
32M1 affixed together are placed on the bottom of the mold 24, with the
clothlike material 32M1 disposed upward of the plate 41, and the
temporary composite layer 20M1 is placed on the ceiling side, with the
temporary second layer portion 22M1 disposed downward of the first layer
portion 21. Then, the rubber material 13 is cast between the temporary
composite layers 20M1 and 30M1, thereby molding the body portion 14.

[0139]Among hydrogen gases generated in the molding process, a gas flowing
to or generated at near the first metal plate 41 escapes to the outside
of a product being molded via the temporary rear-side clothlike material
32M1 and the pressure sensitive adhesive 31 and via the vent holes 41a.
Since minute clearances through which gases are able to pass are present
in the clothlike material 32M1 and the pressure sensitive adhesive 31, it
is unnecessary to additionally provide a venting structure. If residual
gases are present after the rear-side clothlike material 32M2 (see FIG.
1B) is formed by causing the rubber material 13 to impregnate into the
clothlike material 32M1, the residual gases can be purged via the vent
holes 41a.

[0140]Subsequently, the base portion 40 is formed by adhering the second
metal plate 42 to the first metal plate 41 via the resin layer 43,
whereby the molded product shown in FIG. 7A is completed.

[0141]As described above, with the construction shown in FIG. 7A, the
first metal plate 41 and the rear-side clothlike material 32M2 are
prevented from being peeled off from each other by gases generated in the
molding process, thereby making it possible to maintain high adhesion
strength between the body portion 14 and the base portion 40.

[0142]In the molding process, the base portion 40 having the first and
second metal plates 41, 42 affixed together via the resin layer 43 can be
placed on the bottom of the mold 24. In that case, the resin layer 43
must be formed by a material that has heat resistance and permits gases
to pass therethrough. Vent holes similar to those formed in the first
metal plate 41 can also be formed in the second metal plate 42.

[0143]It is possible to form vent holes in the first metal plate 41 of the
unconstrained type having the two-layer structure of the first metal
plate 41 and the resin layer 43, or in the first metal plate 41 of the
non-damping type having only the first metal plate 41, or in the first
metal plate 41 and/or the second metal plate 42 of the five-layer
structure having the first metal plate 41, resin layer 43, second metal
plate 42, resin layer 43, and first metal plate 41, which are stacked in
this order.

[0144]It should be noted that gases to be purged via the vent holes 41a
are not limited to hydrogen gases. Since being are widely applicable to
the venting of gases generated in the molding process irrespective of the
type of rubber and of molding process, the vent holes 41a are useful for
any process in which gases are generated.